The present invention relates to a display system for displaying numeral information stored in a register.
In conventional electronic calculator designs, the digit-capacity of display units is equal to that of a register storing the numeral information introduced or operated. Each numeral information in the register is displayed on a display unit at the corresponding digit position.
In another conventional design, the digit-capacity of display units is a half of that of the register. In the case where the numeral information introduced or operated has digits exceeding the digit-capacity of the display units, the over-flow numeral information is displayed on the display units by closing a selection switch.
The former design is popular and has advantages of being able to see the whole of introduced information or operated outputs at the same time, but needs a number of display units. In recent years, integration of operation circuits enables reduction of the cost thereof and of time for accommodating the operation circuits into a system. Under these conditions, the display units, not suitable to circuit integration technique, are heavy in bulky devices.
For the above-described reasons, the latter design is sometimes used wherein the digit-capacity of the display units is smaller than that of the register and the upper portion and the lower portion of the numeral information are displayed separately. However, in the conventional design, the numeral information is divided into two groups with reference to the last digit of the information stored in the register. It means that the weight of the numeral information in every digit is not taken into consideration in displaying the numeral information.